Angular and axial adjustment mechanism for a printing cylinder

ABSTRACT

A printing cylinder having angular and axial adjustment facility, axial adjustment being by way of a movable trunnion and angular adjustment being by way of a helical gearwheel loose relative to a second gearwheel in a drive train, a double gear loose about a control shaft but axially fast thereto being operable to effect relative angular displacement of the gearwheels and the control shaft being axially fast relative to the movable trunnion.

United States Patent ANGULAR AND AXIAL ADJUSTMENT MECHANISM FOR A PRINTING CYLINDER 2 Claims, 1 Drawing Fig.

U.S. Cl 101/248, 74/395 Int. Cl B4" 13/14 Field of Search 101/248;

References Cited UNITED STATES PATENTS 3/l932 Langston et al. 101/248 5/1935 Rawson 101/248 l0/l94l Potdevin l0l/248 8/1947 Blackley et alt l0l/248 l/l95l Funk l0l/248 Primary Examiner.l. Attorney-Cameron, Kerkam & Sutton Reed Fisher ABSTRACT: A printing cylinder having angular and axial adjustment facility, axial adjustment being by way of a movable trunnion and angular adjustment being by way of a helical gearwheel loose relative to a second gearwheel in a drive train, a double gear loose about a control shaft but axially fast thereto being operable to effect relative angular displacement of the gearwheels and the control shaft being axially fast relative to the movable trunnion.

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1| 46 52 Lo H45 //56 63 61 5| 41' 67 s 59 58 PATENTEU [E62 71 IH MEV ANGIJLAR AND AXIAL ADJUSTMENT MECHANISM FOR A PRINTING CYLINDER This invention relates to an angular and axial adjustment system for a printing cylinder, intended more particularly for multicolor offset or typographic rotary presses.

Multicolor printing requires accurate register of each color and in rotary web presses relative adjustment for each plate is carried out in two coordinates, i.e. transversely and longitudinally of the printed web.

The transverse or margin adjustment is produced by transverse displacement of the plate cylinder with respect to the machine frames.

The longitudinal or register adjustment is produced by angular shift of the plate cylinder with respect to the general line of drive of the machine.

Conventional register adjustment mechanisms often use the relative axial displacement of two helical gearwheels in mesh, resulting in a relative angular shift of the two gearwheel shafts proportional to the axial linear displacement.

When the general drive gearing is helical gearing, all thatis required therefore is to connect the trunnion of the printing cylinder to the corresponding helical drive gearwheel by a sliding coupling allowing a relative axial displacement. The register control mechanism then simply consists of an axial displacement system for the cylinder drive gearwheel. This arrangement has a number of disadvantages however. For example, to obtain high accuracy of operation, the gearwheel displacement must be controlled directly and the adjustment control members must necessarily be on the-general gearing side of the machine, while the margin adjustment control members are on the other side, and this is always an obstacle to the machine minder.

The helical gearwheel of the main gearing transmits a considerable torque and this results in unbalanced transverse reaction forces which in turn result in rotational irregularities in the sliding coupling sufficient to have an adverse effect on the accuracy of adjustment. This disadvantage is particularly serious in fourcolor offset printing.

An arrangement has also been used wherein the gearwheel driving the cylinder and included in the general line of drive of the machine is mounted loosely on the cylinder trunnion. The movement is transmitted by a second gearwheel keyed on the trunnion through the agency of a loose double gearwheel borne by an auxiliary shaft and meshing with both the said gearwheels. The general line of drive may then have spur gearing and the same applies to the double gearwheel, while the gearwheel keyed on the trunnion and the corresponding teeth of the double gearwheel are helical. To produce the angular shift, all that is necessary in that case is to move the double gearwheel axially. In this case there is no sliding system in the transmission of the torque to the cylinder and the torque transmitted by the helical teeth is limited to the driving torque of the single printing cylinder concerned. In such an arrangement, however, the margin adjustment by axial displacement of the cylinder and its trunnions results in a corresponding angular shift so that after each margin adjustment the register must be readjusted.

Other arrangements have also been put into effect but always result in one of the above disadvantages at least.

The present invention relates to a system whereby the margin and register adjustment controls can be disposed on the same side of the machine, neither adjustment is adversely affected by the other, and no sliding assembly is required in the drive torque transmission to the printing cylinder.

The invention relates to printing presses in which each printing cylinder comprises a nonrotating axial displacement control member connected to one of the cylinder trunnions by a coupling without transverse play but allowing free rotation of the trunnion, and in which each printing cylinder is rotated by a system comprising a first gearwheel rigidly connected to one of the cylinder trunnions, a second gearwheel mounted loosely on the same trunnion and forming one of the parts of the general line of drive of the machine, one of these two gearwheels being a helical gearwheel, the other being a spur placement of the loose double gearwheel is rigidly secured to the control member for the transverse displacement of the cylinder. 1

The invention will now be described in greater detail with reference to a specific embodiment given by way of example and illustrated in the drawing.

The single FIGURE is a cross section through the axis of a printing cylinder.

The printing cylinder 1 has trunnions 2 and 3 at each end. On the drive side of the machine, the trunnion 2 is supported in a frame 4 by a bearing 5 fitted into a box 6 held in the frame by means of a ring 7 and screws 8. On the control mechanism side, the trunnion 3 is supported in a frame 10 by a bearing 11 fitted into a box 12 which is slidable in its housing in the frame 10. Its movement is limited by a circlip l3 and a ring 14 secured to the frame by screws 15. A helical gearwheel 18 is keyed on the trunnion 2. A spur gearwheel 19 is mounted loosely on the hub of the gearwheel 18, a self-lubricating ring 20 being interposed. Gearwheel l9 meshes with gearwheel 21 forming part of the general line of drive of the machine.

The margin adjustment system comprises a cap 23 secured to the box 12 and having a screw-threaded aperture 24 in line with the axis of the trunnion 3. A rod 25 is secured by a collar 26 between a plate 27 and a cap 28 secured to the plate 27 by screws 29. Rings 30 allow free rotation of the rod 25 in this assembly. Plate 27 is connected to frame 10 by three screws 31 and three tubular struts 32.

The rod 25 has a screw-threaded end 33 engaging in the screw-threaded aperture 24 in the cap 23 while its other end extending through the machine cover 35 bears a control knob 36.

A rod extends form one side of the machine to the other and its axis is parallel to the axis of the cylinder 1. On the drive side, the rod 40 is supported by a ring 41 in the frame 4 and by a ring 42 on a yoke 43 which is secured to the frame 4 by screws 44. Rod 40 can slide without rotating in the rings 41 and 42. The rod 40 extends through the frame 10 via an aperture 45 and is formed with a screw-threaded bore 46 at its end on the control mechanism side.

Between the frame 4 and the yoke 43 the rod 40 bears a double gearwheel 50 having two sets of teeth 51 and 52 mounted loosely on the two bearings 53 and 54. The gearwheel is held transversely on the rod 40 by a shoulder and circlip assembly.

The helical gearwheel 51 meshes with gearwheel 18. A spur gearwheel 52 meshes with gearwheel 19. The other end of rod 40 is freely engaged in a bore 55 formed in an extension 56 of the cap 23. The screw-threaded end 57 of a rod 58 is engaged in the screw-threaded aperture 46 and is held fixed and so as to be free to rotate in a similar manner as the rod 25, by means of the collar 59, plate 60, cap 61 and rings 62. Plate is secured to the extension 56 of the cap 23 by screws 63. Like the rod 25, the rod 58 extends through the machine cover 35 and bears a control knob 64.

in the operating position, the end of a screw 65 locked by a locknut 66 is engaged in a longitudinal groove 67 in the rod 40. When the control knob 64 for register adjustment is turned in either direction, the rod 58 retained by the collar 59 does not move transversely but, as it is screwed into or out of the aperture 46, provides a transverse displacement of the rod 40, which is prevented from turning by the screw 65. The double gearwheel 50 is driven in this transverse movement proportional to the rotation of the knob 64. Sliding of the spur gearwheel 52 on the matching spur gearing of the gearwheel 19 takes place without any angular shift, but sliding of the helical gearwheel 51 on the matching gearing of the gearwheel 18 results in a relative rotation through an angle proportional to the transverse movement and hence proportional to the rotation of the knob 64.

If this operation is carried out with the machine at rest, the gearwheel 19 connected to the general line of drive of the machine has a high inertia and remains stationary. The relative angular displacement is therefore effected by rotation of the gearwheel 18 and hence of the cylinder 1.

The same applies if the operation is carried out during running, because then the dynamic inertia of the gearwheel 19 is much greater than the inertia of the gearwheel 18 connected to the cylinder 1.

When the margin adjustment control knob 36 is turned in either direction, the rod 25 remains stationary transversely with respect to the frame but results in displacement of the cap 23 and transverse sliding of the box 12 in the frame, resulting in transverse displacement of the printing cylinder assembly 1. At the other end, the outer cage of the bearing 5 slides in the bore inside the bearing box 6.

In this translatory movement for margin adjustment, the extension 56 of the cap 23 produces an identical displacement of the entire register adjustment mechanism, and more particularly displacement of the double gearwheel 50. There is therefore no relative displacement of the gearwheel 50 with the gearwheels l8 and 19 and the initial register adjustment is fully retained.

The invention is clearly not limited to the single embodiment described by way of example but also covers other embodiments differing therefrom only in respect of detail.

For example, the two gearwheels l8 and 19 could also both be helical gearwheels provided that the helix angles of the two sets of teeth are different. lf the actual direction of the helix is reversed, it would be possible in this way to obtain a differential effect which would increase the accuracy of the adjustment.

Similarly, external manual control knobs for the transverse displacement screws for the margin and register adjustment could be replaced by. servomotors protected inside the machine cover and started by an external press button. They could also be replaced by hydraulic, pneumatic or electric jacks, the reaction point of the system for moving the loose double gearwheel always being connected to the cap 23 secured to the printing cylinder.

lclaim:

l. Angular and axial adjustment mechanism for a printing cylinder of a rotary press, the press comprising bearings for each cylinder which is to be adjusted, said bearings supporting the cylinder trunnions and including first means for with respect to the machine frames, a control member, a coupling means connecting said control member to one of the said cylinder trunnions so as to prevent axial play but allow free rotation of said trunnions, second means to displace said control member and thus said cylinder with respect to said frames in a direction parallel to the axis of said cylinder, trunnion and forming one of the parts of the general line of drive of the machine, one of these two gearwheels being a helical gearwheel, the other being a helical gearwheel having a different helix angle from that of the first gearwheel, a double gearwheel comprising two sets of teeth respectively meshing with said first and said second gearwheels, third means for freely mounting said double gearwheel for rotation about a shaft while maintaining said double gearwheel in fixed axial position on said shaft, fourth means for axially displacing said shaft with said double gearwheel in a direction parallel to the axis of said cylinder to thus secure angular adjustment, said fourth means being rigidly secured to and moveable with said control member whereby axial displacement of said cylinder by said second means causes corresponding axial displacement of said double gearwheel, said fourth means being capable of actuation independently of said second means.

2. An angular and axial adjustment system according to claim I, said second and said fourth means being disposed on the same side of the machine.

mg? UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 630445 Dsted December 28, 1971 Inventor(s) Pierre Leuenberger It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Col. 2, line 40, "form" should be -from-; Col. 4, line 11, after "for" --allowing an axial displacement of the cylinder transverselyshould be inserted; line 137;, after the comma, insert -'-a first gearwheel rigidly secured to one of the cylinder trunnions, a second gearwheel mounted loosely on the same-; line 29, "moveable" should be --movab1e-.

Signed and sealed this l th day of July 1972.

(SEAL) Att est R0 BERT GOTT SCHALK Commissioner of Patents EDWARD M.FLETCHER, JR. Attesting Officer 

1. Angular and axial adjustment mechanism for a printing cylinder of a rotary press, the press comprising bearings for each cylinder which is to be adjusted, said bearings supporting the cylinder trunnions and including first means for with respect to the machine frames, a control member, a coupling meaNs connecting said control member to one of the said cylinder trunnions so as to prevent axial play but allow free rotation of said trunnions, second means to displace said control member and thus said cylinder with respect to said frames in a direction parallel to the axis of said cylinder, trunnion and forming one of the parts of the general line of drive of the machine, one of these two gearwheels being a helical gearwheel, the other being a helical gearwheel having a different helix angle from that of the first gearwheel, a double gearwheel comprising two sets of teeth respectively meshing with said first and said second gearwheels, third means for freely mounting said double gearwheel for rotation about a shaft while maintaining said double gearwheel in fixed axial position on said shaft, fourth means for axially displacing said shaft with said double gearwheel in a direction parallel to the axis of said cylinder to thus secure angular adjustment, said fourth means being rigidly secured to and moveable with said control member whereby axial displacement of said cylinder by said second means causes corresponding axial displacement of said double gearwheel, said fourth means being capable of actuation independently of said second means.
 2. An angular and axial adjustment system according to claim 1, said second and said fourth means being disposed on the same side of the machine. 